Fuel injector



Aug. 8, 1933. G. A. GILLEN 1,921,373

FUEL INJECTOR Filed Feb. 12, 1931 2 Sheets-Sheet 1 Aug. 8, 1933. 5, A, GILLEN FUELINJECTOR Filed Feb. 12. 1951 2 Sheets-Sheet 2 INVENTOR mll/ Ka TOR E Patented Au $9 FUEL HNEHECTQDR (George 1i. Gillan, Bronx, N. iL, assignor to Gillan, Kiey, Baker, Syndicate, line, New York, N. K, a Corporation of New York Application February 112, 1931. Serial No. 515,161

7 @laims.

This invention relates to engines of the liquid fuel injection type and special objects of the invention are to provide improved fuel injection mechanism of simple, practical construction, of a design which can be readily manufactured and which will be efficient in operation, par= ticularly as regards the matters of accurately metering and positively injectingthe fuel.

The foregoing and other desirable objects are attained by the novel features of construction, combinations and relations of parts hereinafter disclosed and broadly covered in the claims.

The drawings accompanying and forming part of this specification illustrate one commercial embodiment of the invention but it is to be understood that the structure may be modified as regards this disclosure without departure from the true spirit and broad scope of the invention.

Fig. 1 is a broken vertical sectional view illustrating a form of the invention incorporated in a two cycle engine; Fig. 2 is a broken plan view of the same parts with the valve cover removed; Figs. 3 and a are enlarged cross-sectional details of the injector as on substantially the planes of lines 3-3 and 44 of Fig. 1; Figs. 5

and B are fragmentary vertical sectional views illustrating respectively the back stroke of the plunger for a full power injection stroke and the action of the plunger at the moment of injecting the charge.

In Fig. 1, portions of a two-cycle engine are shown including a cylinder 8, having an air intake port 9 and an exhaust port 10, with a piston 11 operating in the cylinder and controlling said ports.

The fuel injector is located in the head of th engine and is shown as consisting in the main of a plug-like body 12 screwed in the cylinder head and containing pumping and valving means.

Considering the structure in detail, a liquid fuel line is indicated at 13, delivering into a fuel chest 14, communicating by down passes 15, with radial ports 16 opening at different longitudinal points into the main bore 17 of the plug.

Operating in the bore of the plug is a cylindrical valve member 18, having ports 19 disposed longitudinally and radially to align with the ports 16 in the plug body when the head 20 of this valve member, Fig. 5, is seated against the end of the plug member.

The valve member 18 is'hollow back of the head providing a fuel metering chamber and bore 21 for the plunger 22. This plunger in (C11. E -W72) of the fuel metering ports 19 to admit definitely measured quantities of fuel through the aligned ports 16, 19, into the chamber 21, Fig. 5, beneath the end of the plunger.

The downward or inward stroke of the plunger cooperates with the port or ports 19, uncovered in the previous stroke, operating then as a cutoff valve, trapping the admitted liquid ahead of it and forcing the latter to serve as a liquid coupling between the end of the plunger and the bottom of the valve sleeve, which condition results in the plunger positively forcing the valve sleeve inward to uncover the atomizing ports 23 in the same below the end of the plug member,

Fig. 6.

There may be one or a number of the atomizing ports 23 in the valve sleeve back of the head 20 and the construction is preferably such, as indicated in Fig. 6, that the plunger will actually bottom in the end of the bore in the sleeve to expel all the fuel and insure positive opening of the injection ports to a definite extent, regardless of the liquid coupling between the plunger and the sleeve.

Suitable mechanism for operating the parts as described is provided, the same consisting irl the illustration of asingle cam 24. on an overhead cam shaft 25 rotating at crank shaft speed, and operating in sequence a rocker 26 for withdrawing the plunger to charge the valve sleeve and a rocker 27 for forcing the plunger inwardly to inject the fuel against the cylinder pressure.

The rocker 26 for effecting the outstroke of the pump plunger is shown as forked at one end, at 28 to clear the head 29 on the outer end of the valve sleeve and to engage beneath the outstanding lugs 30 on the outer end of the plunger. The opposite end of this rocker is also shown as forked at 31 and as having the branches of this fork pinned at 32 to the head 33, Fig.2, of a slide or plunger 34 slidingly keyed at 35 in a guide socket 36. This sliding member is internally screw threaded to receive the screw shank 37 of a valve tappet 38 having on the back of the same a pinion portion 39 engaged by a rack 40, the purpose of such structure being to enable relative adjustment between the tappet and rocker whereby the stroke of the rocker, and hence the stroke of the injector plunger, maybe predetermined.

The injection rocker 27 is shown as carrying a roller 41 at one end for engagement by the cam and as pinned'at its opposite end at 42 to the plunger, through a slot 43 in the plunger, the

latter enabling the outward or charging stroke, v

of the plunger unhampered by rocker 27. In the illustration, this connection with the outer end of the plunger is actually effected through a link 44 pivoted to the end of the plunger at 45 and thus forming in effect an articulated extension portion of the plunger. A spring 46 is shown interposed between a head 47 on this plunger extension and the end of the rocker to take up the lost motion connection between these parts and to cushion commencement of the charging stroke of the plunger, the end of this slot, however, being located so that with the cam action the plunger will bottom in the end of the sleeve to assuredly force the sleeve inward sufficiently to open the injection ports 23.

A spring 48 disposed beneath the head 29 on the outer end of the sleeve retracts the sleeve to hold the head 20 on the inner end of the same seated against the inner end of the plug at all times when the sleeve is not positively forced inward. v

In the illustration, the sleeve is held against rotation in the plug, so as to keep the ports in the sleeve aligned with the supply ports in the plug, by means of a sliding key connection at 9 Fig. 1 between the sleeve and plug body.

The fuel chest 14 is shown in Fig. 1 as a hollow shell screw threaded on. the outer end portion of the plug at 50 and engaging at its inner end an outstanding abutment flange 51 on the plug, suitable packing being provided to prevent leakage.

For manufacturing reasons, the fuel supply passes 15 are shown as holes drilled up through the bottom of the plug body and then closed by the screw plugs 52. These manufacturing details and other structural features may, however, be widely varied according to different requirements and conditions.

It will be apparent that the outstroke of the plunger and hence the extent of charge taken in behind the plunger may be very accurately determined by adjusting the rack bar 40, which in turn rotates the screw connection of the tappet to, in effect, vary the length of the tappet and hence determine the extent of the cam stroke efiective on the rocker 26. This adjustment thus determines whether one or a number of the ports 19 in the valve sleeve will be uncovered by the plunger. Fig. 5 shows the entire set of radially disposed ports uncovered by the plunger and hence illustrates a condition where the maximum charge has been taken into the valve sleeve. The slotted connection between the plunger and the rocker provided for the instroke, enables the adjusted charge outstroke of the plunger without interference from this rocker and the latter takes up the action where the first rocker leaves ofi, picking up the plunger where it has been left on its outstroke and driving it inward as in Fig. 6, the trapped fuel providing a liquid coupling between the plunger and end of the sleeve, obliging the sleeve to advance to open the injection ports 23 below the end of the plug and the plunger in the final portion of this movement forcing all fuel out of the charge holding chamber. valve providing an extra seal for the injection ports, the head 20 which seats against the inner end of the plug, Fig. 5, also serves, as a hot spot aiding in proper atomization of the fuel being injected into the combustion chamber, it being noted that this head is located within the combustion chamber, fully exposed to the burning products.

In addition to serving as a earers In the two cycle engine disclosed, the parts are timed so that the exhaust products will pass out through the exhaust port 10 as the head of the piston uncovers the latter, the necessary air for combustion being forced in through the air port 9, while uncovered by the piston and the fuel injection occurring when such air has been compressed suficiently to effect ignition.

The parts of the injector are particularly simple and rugged and the device can be produced inexpensively. All parts of the injector are contained in or carried by the plug structure, thus making the substitution of an injector a comparatively simple matter.

A check valve indicated generally at 53 is provided in the fuel line or some other convenient point to prevent back flow of liquid as the plunger starts inward on its injection stroke.

This positively causes the liquid taken in on the back stroke of the plunger to serve as a drivecoupling between the plunger and the valve sleeve. The amount of trapped liquid thus determines the moment of initial injection, a larger amount of liquid producing an earlier injection than a lesser amount of fuel, which is in accord with the desired operation of the engine. Thus, at full load, injection will start earlier and at light load or no load the injection may occur at top dead center. The liquid coupling thus in effect serves as a variable link in the operating connections for properly determining the moment of injection in accordance with the power factor of the engine. The charging ports beingoffset circumferentially are sealed as soon as the valve sleeve moves the distance equivalent to the diameter of one port.

The plug body forms in effect a fuel supply casing for the injector valve sleeve and the plunger operating in the valve sleeve may be considered both as a piston for drawing in variable quantities of fuel into the sleeve and as a plunger for variably timing the injector action through the coupling medium of the entrapped liquid.

What is claimed is:

-1. In a' device of the character disclosed, a supporting structure having a bore with a port opening thereinto, a check valve for holding liquid admitted to said bore, a sleeve sliding in said bore and having a closed end, with a flange portion overstanding the end of the supporting structure, an injection port adjacent said closed end and behind said flange in position to be closed by the supporting structure and a supply port registering with the first port in one position of the sleeve, and a plunger operating in said sleeve to uncover and cover the supply port and to shift the sleeve through the medium of the liquid drawn into the sleeve to uncover the injection port.

2. In a device of the character disclosed, a supporting structure having a bore with a port opening thereinto, a check valve for holding liquid admitted to said bore, a sleeve sliding in said bore and having a closed end, with a flange portion overstanding the end of the supporting structure, an injection port adjacent said closed end and behind said flange in position to be closed by the supporting structure and a supply port registering with the first port in one position of the sleeve and a plunger operating in said sleeve to uncover and cover the supply port and to shift the sleeve through the medium of the liquid drawn into the sleeve to uncover the injection port, the sleeve having a shoulder earers at the' closed end of the same for engagement with the supporting structure.

3. A device of the character disclosed, comprising a plug having an open ended bore and a liquid passage opening into said bore near the open end of the same, a check valve for holding liquid admitted to said bore, a sleeve operating in said bore having a closed end at the open end of the bore and an injection port prising a plug having covered by the plug bore when the sleeve is seated therein, an intake port in the sleeve for registry with the fuel passage in the plug when the sleeve is in its seated position and a plunger operating in said sleeve to cover and uncover the intake port and to eject liquid through the injection port.

t. A. device of the prising a plug having an open ended bore and a liquid passage opening into said bore near the open end of the same, a check valve for holding liquid admitted to said bore, a sleeve operating in said bore having a closed end at the open end of the bore, an injection port covered by the plug bore when the sleeve is seated therein, an intake port in the sleeve for registry with the fuel passage in the plug when the sleeve is in its seated' position and a plunger operating in said sleeve to cover and uncover and to eject liquid through 'the injection port, said sleeve having an outstanding head at its closed end for engagement with the end of the plug.

5. A device of the character disclosed, coma bore open at one end and liquid supply ports opening into said bore at difierent longitudinal positions therein, a check valve for holding liquid admitted to said supply ports, aclosed end sleeve operating in said bore having ports for registry with said plug ports and an injection port for closure by the bore of the plpg, a plunger operating in the sleeve, means closed end, an injection character disclosed, comthe intake port k for imparting a variable outstrolre to said plunger to uncover different ports in the sleeve and for imparting an instrolre to the plunger suihcient to open the injection port, irrespective of the length of the stroke including cam means and oppositely operating rockers actuated thereby and having connection with the plunger to com-i pensate for the variable stroke aforesaid.

6. In a device .of the character disclosed, a supporting structure having a bore, a liquid chest and supply passages extending from said chest and opening into the bore at different lengths of the same, a check valve for holding [liquid admitted to the liquid 1 chest, a sleeve having a port back of said closed end and ported to register with the supply passages, a plunger operating in the sleeve, means for withdrawing the plunger to a variable extent and for advancing the same to a predetermined position, a shoulder-on the sleeve for cooperative engagement with the supporting structure to definitely position the same therein and spring means acting on the sleeve to hold the same with the shoulder engaged with the supporting structure.

W 7. In a device of the character disclosed, the combination with a liquid supply casing and a closed end ported valve sleeve operating therein,

' induce a quantity of liquid from the supply casing through the port into thevalve sleeve and operative on its pump stroke to advance the valve sleeve through the medium of the liquid previously entrained therein and an injection port in the valve sleeve adapted to-be opened in the travel of. the valve sleeve imparted thereto by said liquid coupling.

e GEORGE A. GILLEN. 

